Goal: Produce a poster, blog post or short presentation to communicate Melton’s team’s breakthrough, including connections to the IBBio course.

Role: You are science communicators.

Audience: Your peers – high school students and teachers.

Scenario: Stem cells and diabetes are both headline-grabbing stories. As we develop more treatments for diseases using stem cells, the public need to be well informed of the reality of what is happening – and inspired by the future.

Explain that Type 1 diabetes is “an autoimmune metabolic condition in which the body kills off all the pancreatic beta cells that produce the insulin needed for glucose regulation in the body.” [article, paragraph 14]

Outline the usual treatment needed for type 1 diabetes.

Outline the properties of stem cells.

Explain how stem cells differentiate to become differentiated cells.

Describe the work of Melton’s team to create beta-cell lines derived from stem-cell lines.

Outline the proposed treatment for type 1 diabetes through implanting the newly-produced beta-cells.

Discuss any caveats or limitations to the method.

Discuss any ethical implications for the use of stem cells in this manner.

Define any new or technical terms used (or discovered in your research) for the audience.

Going Further

Distinguish between type 1 and type 2 diabetes.

Evaluate whether this method would be as effective for type 2 diabetes as for type 1, with reasons.

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Teacher Notes

This could be used to teach part of the homeostasis topic once students know about stem cells, or as a review tool for later in the course.

Students should refer to the subject guide to check their use of terminology and to regulate the depth of explanation.

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Connecting Type II Diabetes

Here is Doug Melton talking about how we might use hormones to treat Type II diabetes:

Wow. Two papers published in Nature Methods have outlined a new technique which allows researchers to track development of embryos (in this case Drosophila melanogaster), in real time. By taking simulataneous multi-view microscopic images of the developing embryo, individual cells can be tracked in real time. The methods are described in more detail at Nature News here.

Have a look at the amazing results below, as a fruitfly embryo develops into a larva, ready to hatch. The two views are the dorsal (upper side) and ventral (lower side) view of the same embryo. See if you can pick a cell and watch its path of development.

Think about how this links to IB Biology topics of cell division, cell specialisation and embryonic development. How does a stem cell know what type of cell to become? If you look closely, there’s a scale bar in the bottom-right. Take a snapshot and calculate the actual length of the embryo.

With links to stem cells, genetic engineering and biotechnology, homeostasis and the kidney, the current science outlined in this TED Talk by Anthony Atala is amazing. It includes a demonstration of a real kidney being printed and a student who has an engineered bladder and now lives a normal life. Wow.

With huge numbers of people waiting for kidney transplants, is this the future of transplant medicine?

Theory of Knowledge

The embryonic stem cell debate generates strong and emotive knowledge issues, which is evidenced by the fact that the case was passed all the way up to the European Court of Justice. There are many stakeholders in embryonic stem cell research, each with their own knowledge claims and beliefs.

With this recent ban on patenting methods based on the destruction of embryonic stem cells, we add the elements of patenting and intellectual ownership (and of course the knock-on effects to funding, progress and public perception).

To what extent does the embryonic stem cell debate highlight potential conflicts between the areas of knowledge of the natural sciences and ethics and between the ways of knowing of emotion and reason?

After reading through, understanding and discussing the resources, what knowledge issues can you identify?

This is the predictable and perennial question that comes up from at least one student when we are looking at stem cells, genetic engineering, cell differentiation and transplanting. Until now, the answer has (perhaps in an oversimplified way) been ‘no’.

To treat lymphoma, bone marrow cells are replaced, and are all the same. The trachea transplant was a pre-existing trachea simply coated in the patient’s stem cells to prevent immune rejection. Skin transplants are basically sheets of epidermis that cover a wound, yet do not have the intricate functions of original skin: temperature regulation, secretion, senses. The bladder is a bag.

2. Strip of all cells and DNA, using a detergent. Only the collagen ‘scaffold’ remains, as in the image of the decellularised heart to the right.

3. Coat the scaffold with the recipient’s stem cells.

4. Ensure that the blood supply is adequate and will provide the right signals for differentiation.

What is amazing in this case is how the cells ‘knew’ what specialised cells to become. The leader of the research group, Dr. Doris Taylor, puts it down to the mechanical stimulus of the pressure of the blood in the vessels and chambers and chemical signals from growth factors and peptides that remained on the stripped heart structure.

They even went as far as replacing a healthy rat’s heart with one of these new hybrid hearts. The rat survived for the trial, but she says they need to focus on producing more muscular hearts in order to ensure long-term survival of transplant recipients.

Food for thought:

Read the whole article and some of the links within it. Discuss these questions:

1. What are the potential uses for this kind of transplant technology?

2. What are the current limitations of this method and how might they be overcome?

3. What are the ethical issues related to using hybrid (pig-human) organs in medical transplants? How would you feel if you were the patient?

4. Who are the various stakeholders in this technology and what are their viewpoints?

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